Intake Question

Pollmann

1982 XS400
Messages
4
Reaction score
0
Points
1
Location
Cayuga, Ontario, Canada
Hey Guys,
In between my carbs and my engine there are these two holes in the attachments. One just after each carb (they are labelled as number 6 on the attached picture). On my xs400, one of them is capped off and the other has a hose coming out of it. The end of the hose looks like it used to be attached to something but I'm puzzled why one would run somewhere and the other is capped, shouldn't both carbs be running identically? The hose feels to be a vaccuum of some sort, it is sucking in air when the bike is running, but the bike runs pretty similar with it open and when i plug it. I've checked my manual and it doesn't shed much light on the issue.

I'm just wondering what the purpose of these two holes are and why one is capped and the other has a open hose on it. Are these supposed to both be capped?

Any help would be greatly appriciated :) thank you!
 

Attachments

  • INTAKE.png
    INTAKE.png
    51.6 KB · Views: 275
Those are vacuum ports, used when syncing the carbs. One is typically plugged, the other (with the hose) connects to the stock petcock which is vacuum operated. I'm guessing you must have an other than stock petcock?
 
Those are vacuum ports, used when syncing the carbs. One is typically plugged, the other (with the hose) connects to the stock petcock which is vacuum operated. I'm guessing you must have an other than stock petcock?

Thank you so much, that makes complete sense. I do have a stock petlock. I noticed the spot for a tube to attach on it when I had it off to seal the tank and didn't put two and two togther. Great help, thank you! :D
 
Back
Top